GAMMA KNIFE RADIOSURGERY FOR GLOMUS JUGULARE TUMORS

Objective Stereotactic radiosurgery has been used increasingly for the treatment of glomus jugulare tumors. The authors report their experience treating these tumors using gamma knife radiosurgery (GKRS), documenting the clinical and radiological outcome. Methods A retrospective analysis identified 17 patients with glomus jugulare tumors who underwent GKRS. Besides analysis of clinical outcome, a radiological volumetric analysis was also performed after treatment. Results There were 15 women and two men (average age, 63.1 yr) with a median follow-up period of 48 months. The median radiosurgical dose to the tumor margin was 15 Gy (range, 13-18 Gy). Eight patients (47.1%) improved clinically, two (11.8%) worsened, and seven (41.2%) were unchanged. No relationship between internal auditory canal dose and hearing loss was recorded. Tinnitus and otalgia were the symptoms that responded most favorably to GKRS. No patients experienced new lower cranial nerve palsies after GKRS. Tumor volume showed a transient increase in seven patients. Analysis of tumor volume at the time of the last magnetic resonance imaging scan recorded a decrease in eight patients, an increase in four patients, and no change in five patients. Conclusion GKRS is a safe, effective treatment for glomus jugulare tumors, particularly in patients with preserved glossopharyngeal and vagus nerve function, after surgical recurrence, in the elderly, and in patients with serious preexisting medical conditions. Longer follow-up periods are required to assess long-term effects.